Shielded ignition coil



June 24, 1958 c. s. MARDEN 2,340,622

- SHIELDED IGNITION con.

Filed Feb. 2. 1955 j'nUenZ-ar ('arZeZam 52 jfaraen 2,840,622 I SHIELDED IGNITION COIL 1 Carleton S. Marden, Waltham, Mass., assignor to National Products Corporation, Boston, Mass., a corporation of Massachusetts Application February 2, 1953, Serial No. 334,662

8 Claims. (Cl. 123-148) This invention relates to electrical connections between high voltage components such asthe spark coil and distributor of an internal combustion ignition system, and particularly to electromagnetic shielding of such connections to prevent radio interference -generated bythe high tension current.

It is common practice, particularly in military vehicles, to shield the cables leading between the high voltage terminals of such components. The recent trend is toward completely shielding the cables and all the com ponents. While it is possible for the manufacture of the nector for a spark coil;

. i a Patented June 24, The shielded connector is particularly adapted for assembly in a harness comprising an ignition cable having a metallic shield, the aforesaid cable entrance including grounding means for attaching the end of the shield to the'hood short of the end of the cable, and the sheath on the end of the cable being spaced from the cable en-.

trance and loosely supported on the end of the cable. v

Preferably the hood has at one end a mouth portion adapted to telescope over and electrically contact the aforesaid tubular casing so that the hood encloses the terminal, hood and casing entirely shielding the com- 'ponent, and the hood includes a detachable closure at the other end thereof and means interengaging the closure and hood externally of the hood to aliord unimpeded access to the terminal and cable end when the hood is attached to the casing.

For the purpose of illustration a typical embodiment of the invention is shown in the accompanying drawings vehicle to assemble the component and cable shields on be connected to the terminals-of thevarious components and the cable ends are provided with connectors adapted to make electrical contact with the terminals of the components so that the manufacturer may complete the connections without soldering or otherwise assembling the system with the aid of special tools. f

Notwithstanding the desirability of such a harness it is dilficult to manufacture a shield with the attached connectors in proper positionto fit the terminals of the component.

One object of the present invention is to provide a harness including a shield adapted for easy attachment to a high voltage component which is particularly" adapted to preassembly, and which has sufiicient flexibility in the electrical connection to facilitate attachment ofthe shield and connector.

A further object is to provide ashielded connection for socket terminal member, the shielded connector comprising a tubular metallic hood adapted to telescope over the casing and shield said terminal, a cable entrance .into the hood, suitable means for connecting the cable to the aforesaid socket terminal member including an insert fitting in said member, and a resilient sheath gripping the connecting means, the sheath having a sleeve portion adapted to engage the outside of the terminal member and hold the connecting means attached thereto. Preferably the connecting means further includes a clip for attachment to the cable, the slip being formed to telescope over and grip the aforesaid insert. Preferably the insert is a cylindrical plug fitting in the socket terminal member, and the sleeve portion of the sheath is of greater internal diameter than the plug so that it is adapted to expand and engage outside the terminal member.

various spark coils.

in which: W

Fig. 1 is an exploded isometric view of a shielded con- Fig. 2 is a plan view ofthe shielded connection assembled in a harness, parts being omitted; and

Fig. 3 is a side elevation partly in section of the har ness assembly. I i i In the figures the'spark coil, which is illustrative of a high voltage component, comprises a metallic casing 1 enclosing the coil proper 5, a metallic cap member 1 attached as a part-of the casing 1, an insulating member 2 including a tubular socket 2a, low voltage-terminals 3 extending from the insulating member 2 and a cupshaped female terminal 4 seated within the tubular member 2a1 andconnected by a wire 6 to the coil 5.

The shielded connector includes a tubular hood 11 having a cap 12, and three cable entrances 13 for admitting the cable 14 within the hood. The cable 14 includes a braided shield 16, insulation 17 and a conducting wire 18.. .The cable entrances 13 are each provided with 'a nut 19 for clamping the end of the braided shield '16 and grounding the end of the shield to thecable entrance 13. The end of the shielding16 stopsshort of the end of the insulation 17 and the conductor 18, these parts'of the cable extending through the entrance 13 to within the shield. In the case of the low voltage terminals the conductor 18 may be attached by means of a nut 21. U

In the case of the high voltage socket 2a the insulation .17 and conductor 18 extend into a sheath of rubber-like material 22. The insulation'17 beinggripped by; the

Th sheath 22 fits over the upper end of a metal plug ,26 generally of cylindrical shape. The plug is radially slit to form resilient bifurcations 27 designed to fit yieldingly with thefemale terminal 4 of the spark coil. The ,tubular plug 26 extends above the tubular socket2a and maybe made many sizieto lit the female terminal 4 of Variations in the diameter of the bifurcated portions 27 of the plug do not require any change in the.coil clip 23. or sheath 22. This interchangeability of the plug affords a great economy in'eost and time in the assembly andattachment of the harness. The sheath 22 is provided witha sleeve portion 25 of of the tubular socket 2a. In this position the sheath firmly grips the socket 2a holding the. coil clip 23 and plug 26 in firm electrical connection with each other and ,with the temaleterminald. The sleeve 25-also forms waterproof seal around the high voltage terminal socket 2a excluding condensation and other foreign substances to Fig. 3 the sheath 22 is loosely'held on thecable insnlation 17, that it isnot fixedrigi'dly with relationfto the hood 11. Consequently after the hood 11 istelesopingly attached to the casing 1, removal of the cap-12 permits access to thesheath 22 for firm attachment of-the sheath to the terminal socket. The threading on the cap and hood is external of the hoodso that when the cap is removed there is no obstruction of the terminals 3 and 4.

It can, be seen'from the foregoing description that the present shielded connection is readily adapted to 'fit various spark coils or like components, that it is simply assembled in an ignition harness, and provides a reliable electromagnetic shield and a waterproof seal for the high voltage terminal. j

It should be understood that the present disclosure is for the purpose of illustration only and that this invention involves all modifications and equivalents which fall within the scope of the appended claims.

Iclaim: I j

1. For connecting an ignition cable to a high voltage component having a cylindrical casing and a tubular socket terminal member, a shielded connector comprising a tubular metallic hood adaptedto telescope overv the casing and shield said terminal, means forming acable entrance into said' hood, means for connecting said cable to said socket terminal member including a removable in sert lltting in said member, and an elastic sheath resiliently gripping said means, said sheath having a sleeve portion adapted to engage the outside of said terminal member to hold said connecting means attached thereto and enclose and seal said sockete e 2. For connecting an ignition cable to' a high voltage component having a cylindrical casing and a tubular socket terminal member, a shielded connector comprising a tubular metallic hood adapted to telescope over the casing and shield said terminal, means forming a cable entrance into said hood, means for connecting said cable to said terminal member including a removable insert'fitting in said member, and a clip for-attachment to said cable, said clip being formedto telescope over and grip said insert, and. an elasticsheath resiliently gripping said clip,'said sheath having a sleeve portion adapted to engage the outside of said terminal member to hold said connectf ingmeans attached thereto and enclose and seal said socket. I

3; For connecting an ignition cable to a high voltage component having a cylindrical casing and a tubular socket terminal member, a shielded connector comprising a tubular metallic hood adapted to telescope over the easing and shield said terminal, means forming a cable entrance into said hood, means for connecting said cable to said terminal member including a removable, cylindrical insert plug fitting in said member and a clip for attachment to said cable, said 'clip being formed to telescope over and grip said insert, and an elastic sheath resiliently gripping said clip, said sheath having a sleeve portion of greater internal diameter than said plug adapted expandconnecting said cable tosaid terminal member, and an elastic sheath resiliently gripping said means, said sheath having a sleeve portion adapted to engage the outside of said terminal member to hold said connecting means attached thereto and enclose and seal said socket, and said sheath being spaced from said cable entrance and loosely supported on said end of the cable.

5. A harness for connection to a high voltage component having a cylindrical casing and a tubular socket terminal member, comprising a tubular metallic hood adapted to telescope over the casing and shield said terminal, an ignition cable having a metallic shield, means forming a cable entrance into said hood, grounding means attaching the end of said shield to said hood short of the end of the cable, insert means fitting in said socket for connecting said cable to said terminal member, and an elastic sheath resiliently, gripping said means, said sheath having a sleeve portion adapted to engage the outside of said terminal member to hold said insert means attached thereto and enclose and seal said socket, said sheath being spaced from said cable entrance and loosely supported on said end of the cable, said hood including a detachable closure at the other end of the hood, and means interengaging said closure and hood externally of the hood to afford unimpeded access to said terminal and cable whenthe hood is attached to the casing.

6. A harness for connection to a high voltage component having a cylindrical casing and a tubular socket terminal member, comprising a tubular metallic hood having at one end a mouth portion adapted slidingly to telescope over and electrically contact said casing so that said hood encloses said terminal and said hood and casing entirely shielding said component, an ignition cable having a metallic shield, means forming a cable entrance into said hood includinggrounding means for connecting the cable shield to said hood, insert means fitting in said socket for connecting said cable to said terminal member, and an elastic sheath resiliently gripping said means, said sheath having a' sleeve portion adapted to engage the outside of said terminal member to hold said insert means attached thereto and enclose and sealsaid socket, said sheath being spaced from said cable entrance and loosely supported on said end of the cable, said hood including a detachable closure at the other end of the hood, and means interengaging said closure and hood externally of, the hood to afford unimpeded access to said terminal and cable when the hood is attached to the casing. I

7. A harness for connection to a high voltage component having a cylindrical casing and a tubular socket terminal member, comprising a tubular metallic hood having at one end a mouth portion adapted slidingly to telescope over and electrically contact said casing so that said hood encloses said terminal and said hood and casing entirely shield said component, an ignition cable having a metallic shield, means forming a cable entrance into said hood including grounding means for connecting the cable shield to said hood, means for connecting said cable to said terminal socket member including a cylindrical insert plug fitting in said socketand a clip for attachment to said cable, said clip being formed to telescope over and grip said plug and an elastic sheath resiliently gripping said connecting means, said sheath having a sleeve portion adapted to engage the outside of said terminal member to hold said connecting means attached thereto and enclose and seal said socket, said sheath being spaced from said cable entrance and loosely supported on said end of the cable, said hood including a detachable closure at the other end of the hood, and means interengaging said closure and hood externally of the hood to afford unimpeded access to said terminal and cable when the hood is attached to the casing. I

8. For shielding an ignition coil having a cylindrical metal casing and a plurality of spaced terminals including a tubular socket terminal member, a connector comprising a tubular metallic hood having a mouth portion slidingly fitting over said casing, a plurality of cable cntrance forming means on said hood for receiving cables for connection to said terminals respectively, said mouth portion adjustably fitting said casing so that said openings may be positioned in proper relation to said terminals, a removable insert plug fitting in said socket member, a clip formed to telescope over and grip said insert, and

an elastic sheath resiliently gripping said clip, said sheath References Cited in the file of this patent UNITED STATES PATENTS Sublette Oct. 5, 1920 'Wright et a1 June 14, 1932 Blount July 16, 1935 Hallett Jan. 16, 1945 Burrell Aug. 30, 1949 Elliott Sept. 28, 1954 

